The study focused on the WaveLight Allegretto Wave Eye-Q excimer laser system (WaveLight/Alcon) used to perform PRK and LASIK.

“These data are comparable or even better than those that supported FDA approval of this device in 2007,” Esmeralda Costa, MD, said. “The WaveLight Wave Eye-Q excimer laser system is effective and predictable in myopia and myopic astigmatism correction, leading to good visual and refractive outcomes. It’s fast, with less tissue ablation, and has a good safety profile.”

Patients and preoperative values

The study included 241 eyes of 187 patients (123 women and 64 men) with a mean age of 34.3 years (range: 20 to 54 years). Of the 241 eyes, 219 underwent PRK and 22 had LASIK.

Outcomes and conclusions

Both groups combined had a mean postoperative UCVA of 1.03. The improvement in mean UCVA yielded an efficacy index of 0.97. Results showed that 77.2% of eyes had final UCVA of 20/20 or better, and 95.4% of eyes had final UCVA of 20/25 or better.

Predictability data showed that 88% of eyes had a final spherical equivalent within 0.25 D, 98% of eyes had a final spherical equivalent within 0.50 D and all eyes had a final spherical equivalent within 1 D.

In the PRK group (219 eyes), 198 eyes had a final spherical equivalent within 0.25 D and 217 eyes had a final spherical equivalent within 0.50 D.

In the LASIK group (22 eyes), 14 eyes had a final spherical equivalent within 0.25 D and 19 eyes had a final spherical equivalent within 0.50 D.

BCVA improved by one Snellen line in 28 eyes (11.6%) and two lines in three eyes (1.2%). Data showed three cases of moderate haze in the PRK group, with one patient losing one line of BCVA. No patient lost more than two lines of BCVA, and no patients required re-treatment.

“We introduce the data on the machine,” she said. “We don’t do marks on the patients. The laser has a perfect centration method.”

Dr. Costa explained why she and colleagues prefer PRK over LASIK.

“We are coming back to the surface right now. There’s a general tendency toward that,” she said. “The second reason is because we are a university hospital, so we have lots of residents and all of them perform refractive surgery. PRK is safer than LASIK, of course.” – by Matt Hasson